Validation of a simplified food frequency questionnaire for the assessment of dietary habits in Iranian adults: Isfahan Healthy Heart Program, Iran

Background: dietary assessment is the first step of dietary modification in community-basedinterventional programs. this study was performed to validate a simple food frequencyquestionnaire (sffq) for assessment of selected food items in epidemiological studies with alarge sample size as well as community trails.methods: this validation study was carried out on 264 healthy adults aged ? 41 years old living in 3district central of iran, including isfahan, najafabad, and arak. selected food intakes were assessedusing a 48-item food frequency questionnaire (ffq). the ffq was interviewer-administered, whichwas completed twice; at the beginning of the study and 2 weeks thereafter. the validity of this sffqwas examined compared to estimated amount by single 24 h dietary recall and 2 days dietary record.validation of the ffq was determined using spearman correlation coefficients between dailyfrequency consumption of food groups as assessed by the ffq and the qualitative amount of dailyfood groups intake accessed by dietary reference method was applied to evaluate validity. intraclasscorrelation coefficients (icc) were used to determine the reproducibility.results: spearman correlation coefficient between the estimated amount of food groups intakeby examined and reference methods ranged from 0.105 (p = 0.378) in pickles to 0.48(p < 0.001) in plant protein. icc for reproducibility of ffq were between 0.47-0.69 in differentfood groups (p < 0.001).conclusion: the designed sffq has a good relative validity and reproducibility forassessment of selected food groups intake. thus, it can serve as a valid tool in epidemiologicalstudies and clinical trial with large participants.